the short answer ... yes and indefinitely (in theory).
Bacteria does not grow at minus 18C so storing meat well sealed in a chest freezer with no defrost cycle set at minus 18C or lower, will keep (almost) indefinitely. The rule of thumb is 6 months.
As for the yes....There is a misconception that raw eggs are unsafe which, at least in Canada, is not true. I think that goes for any developed country.
But the key concept to understand is control your combination of temperature & time:
use fresh meat, Keep eggs and meat cold, mix quickly and form burgers quickly to avoid letting them warm up.
Freeze in one layer on separate cookie sheets (metal ideally) as soon as you finish.
Ideally, do not defrost but cook frozen on the grill.
short time combine with cold temperatures is the way to control bacterial growth hence making food safe.
When cooking, you should cook burgers through and through (no red or pink).
Hope this helps?